阅读短文，下列问题
B
Mr. Jenkins liked all kinds of delicious food. As an important officer, he was often asked to dinner. The shopkeepers tried their best to fawn on（巴结）him. They knew it was good for their business. Now the officer got fatter and fatter. He could hardly go upstairs at home and had to sleep downstairs. He often felt tired if he walked or did some housework. He was worried about it and had to go to a doctor.“Stop eating much fat（脂肪） and sugar,Mr. Jenkins,” said the doctor.“Or it will be worse for your health!”It was difficult for the officer to do it. He wouldn't do as the doctor said. He found something was wrong with his heart a few months later. Now he thought the doctor was right. And he had to be in hospital.
“You must lose weight（减肥）,sir,”said the doctor,“unless you want to die soon!” “Could you tell me a way to lose weight, please?”“You must do some exercise first.” “Which exercise?” “To move your head from side to side when you are invited to dinner!”
x－2＝0的两个根，且－
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